This invention relates to improvements in fuel cell adapter systems for use in combustion tools. As exemplified in Nikolich U.S. Pat. Nos. 4,403,722, 4,483,474, 4,522,162, and 5,115,944, all of which are incorporated by reference, it is known to use a dispenser to dispense a hydrocarbon fuel to a combustion gas-powered tool, such as, for example, a combustion gas-powered fastener-driving tool. Such fastener-driving tools and such fuel cells are available commercially from ITW-Paslode (a division of Illinois Tool Works, Inc.) of Vernon Hills, Ill., under its IMPULSE trademark. In particular, a suitable fuel cell is described in Nikolich U.S. Pat. No. 5,115,944, listed above.
A standard system for attaching a fuel cell to a combustion tool is known, i.e. placing the fuel cell into the combustion tool with a metering unit such as a valve, and having no adapter. This system has the advantage of being compact, however it does not protect the female metering unit inlet from dirt and other debris. Also, when not using an adapter, a protective cap or blister pack is needed for transporting the fuel cell.
There is another known fuel cell attachment system for combustion tools, where a sleeve-like seal support adapter attaches to a fuel cell and creates a seal for joining the fuel cell stem and a male joiner from the combustion tool. However, this adapter system does not protect the fuel cell from dirt and other debris. Another disadvantage is that the presence of this adapter alone is believed to diminish the life and capacity of the fuel cell.
One disadvantage of conventional combustion tool fuel cells as described above is that the conventional alignment structures employed for aligning the corresponding stems or passageways of the fuel cell and the tool fuel metering unit or valve do not provide consistent coaxial alignment of these passageways, which may lead to wasted fuel, shortened fuel cell life and less than optimal performance.
A related design problem of conventional combustion tool fuel cells is that proper alignment needs to be maintained between the fuel cell stem and the tool metering valve nipple, both during installation of the fuel cell into the tool and when exposed to the relatively rough, construction site or workshop working environment of such tools.
Maintaining a proper seal between the fuel cell stem and the tool metering valve nipple is also a problem, in that the seal needs to prevent the escape of fuel, while accommodating the sliding action of the fuel cell stem relative to the seal and the nipple as the fuel cell is inserted into, or withdrawn from the tool. Upon insertion into the tool, the fuel cell stem must be depressed into the fuel cell to permit the release of fuel. Further, if the fuel cell is removed from the tool before it is empty, the stem must be allowed to return to its closed or extended position to prevent fuel leakage.
Accordingly, there is a need for an improved fuel cell attachment system that protects the fuel cell from dirt and other debris while in use. In addition, there is a need for a fuel cell adapter system which maintains a positive, aligned engagement between the fuel cell stem and the tool fuel metering valve nipple, both during operation and insertion or removal of the fuel cell from the tool.